Template for achieving anode-free and anodeless batteries

Problem

Anodeless or anode-free liquid, solid, and hybrid liquid-solid batteries hold tremendous promise, offering lower cost in parallel to over 50% higher energy by weight and by volume. However because of the poor Coulombic efficiency (CE), which leads to poor cathode utilization, rapid capacity fade during cycling, an unstable solid electrolyte interphase (SEI) and ultimately dendrites, such cells have not been commercially viable.

Solution

This invention discloses a template material that may be employed on the anode side of a battery that will allow “anodeless”/“anode-free” operation of a battery. The anodeless battery can operate on various alkali ions such as lithium, sodium, potassium, zinc, calcium, magnesium, aluminum etc., and various electrolytes such as liquid-based, solid-state, hybrid liquid-solid. This will save cost and increase the cell energy by eliminating the need for graphite or thick metal foils to be attached to the current collector. Rather the cell can be run with the active ion loaded into the cathode—i.e., in normal discharged state, with the template material being placed directly on the anode-side current collector. This invention overcomes the long-recognized problem that in an anodeless configuration, safe battery cycling is not possible because of metal dendrites that emerge on the anode side and because of the associated unstable solid electrolyte interphase (SEI). The template material is a compound that is ionophilic and contains the ionically active element as one of elemental components in its composition.

Features and benefits

Researchers employ carbon-based templates such as various graphenes as well as metallurgical templates such as gold layers. All these existing embodiments yield poor CE (defined as ions out/ions in) early in cycling because the fraction of alkaline ions react irreversibly with the template. We overcome this problem by having the template contain the active ion as part of the metallurgical compound and by having the compound contain significant amount of vacancies. This allows the active ions to freely move in and out of the template, plating uniformly on the surface, while not being trapped irreversibly.